Yes, dairy products like milk, yogurt, or cream can help neutralize spices in gravies by diluting the concentration of the spices and coating the palate, reducing the sensation of heat.
Dairy products contain fats and proteins, particularly casein, which bind to capsaicin, the compound responsible for the heat in chili peppers and other spices. This binding action effectively reduces the amount of capsaicin that interacts with the pain receptors in your mouth. Furthermore, the creamy texture of dairy coats the tongue and palate, creating a barrier that prevents the spices from directly stimulating the taste buds. The water content in dairy also helps to dilute the overall concentration of the spices, lessening their impact. Different dairy products have varying levels of fat and protein, so their effectiveness in neutralizing spices can differ. For example, full-fat yogurt or cream will generally be more effective than skim milk. The amount of dairy added also plays a crucial role; a small splash might not be enough to significantly reduce the spiciness, while a larger quantity will have a more noticeable effect.
Add dairy gradually and taste as you go. Adding too much dairy at once can alter the flavor profile of your gravy significantly, potentially making it bland or overly rich. Start with a small amount and increase until you reach the desired level of spiciness.